Against the King's Indian Setup

The idea

After 1...Nf6 2.Nf3 g6 3.Bf4 Bg7 4.e3 d6 5.Be2 O-O 6.h3, both sides have quiet setups. Against the fianchetto, White often prefers Be2 to Bd3, and h3 gives the bishop on f4 a retreat on h2.

Plans for White

Castle, then play c3 or c4 and Nbd2. White wants a solid center and to stop Black's freeing ...e5. The Jobava London, with Nc3 instead of c3, is a sharper option against this setup.

Plans for Black

Prepare ...e5 with ...Nbd7 or ...Nc6, or play ...c5 against d4. The bishop on g7 is strong on the long diagonal, so opening the center helps Black. Black's king is safe after castling, so there is time to prepare the break.

Watch out for

For White, ...e5. If Black gets in ...e5 with tempo, for example by hitting the bishop on f4, White's setup loses its point.

For Black, ...Nh5 to chase the bishop. It is a common idea, but after h3 the bishop can drop to h2, so the knight on h5 may end up out of play.